Carmakers favor EPA proposal for real-world mpg testing

Carmakers are leaning to see a proposal requiring them to road test vehicles to verify mileage claims. The US Environmental Protection Agency is proposing to require car makers to perform "supplemental test track audits" of light vehicles, along with laboratory testing. The proposal came following recent restatement of EPA ratings on several vehicles by Hyundai, Kia and Ford.

Carmakers, however, are unclear on how such tests should be conducted since variables wind speed, temperature and pavement conditions should also be factored. AutoPacific analyst Dave Sullivan remarked that “more realistic and more real-world testing" is a good idea, but noted that he is not sure “what implementation will be like."

According to The Wall Street Journal, the proposal would make real-world driving trials more rigorous and reflect air resistance and rolling friction on a test track rather than in a test lab -- factors that could affect fuel economy considerably.

Consumers have been complaining on the typical difference between how far they could actually travel and how far carmakers tell them they could travel. EPA said in a statement that augmenting its pre-production procedures with post-production audits of real world factors will help ensure that “data used in EPA labels accurately reflect the vehicle consumers find on dealer lots.”

EPA added that proposal would be subject to a public notice, comment and rulemaking process. Ford restated mpg ratings on several hybrids in June while Hyundai is facing a lawsuit in South Korea over claims that it overstated figures in the Santa Fe crossover.

In 2012, Hyundai and Kia apologized and compensated owners for overstating mileage figures on light-vehicle models in the United States. A spokesman for Ford remarked addressing the mpg inconsistency across the industry is an “important effort” by EPA.